Apparatus and process for loading propellant in fin type round



G. c. Po'rTs 3,137,198 RocEss FOR LOADING PROPELLANT Jun 16, 1964 -FIGLI.

United States Patent Uffice 3,137,198 Patented June 16, 1964 3,137,198 APPARATUS AND PROCESS FOR LOADING PRPELLAN'I IN FIN TYPE ROUND George C. Potts, Philadelphia County, Pa., assiguor to the United States of America as represented by the Secretary of the Army Filed Mar. 13, 1963, Ser. No. 265,317 9 Claims. (Cl. 86-31) (Granted under Title 35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by orfor the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to an apparatus and process for filling a cartridge case with propellant when the projectile to which the case is crimped has tail fins for assistance in stabilizing liight of the projectile with a usual low rate lof spin caused by rifling in a gun barrel.

An object is to be able to fill the cartridge case with a predetermined quantity of a propellant without having to fill the case with propellant from a hole in the base of the case when such a plugged hole has been found objectionable and given to leakage of gas after the propellant has been fired. Another object is to overcome the danger of having to push the finned rear end of such a projectile into a bed of propellant when some of the propellant grains may fracture and have an increased burning rate resulting in higher pressure than had been planned for.

Projectiles which are stabilized in flight by both spin and fins when in fixed ammunition require a cartridge case having a forward end of smaller diameter crimped to a projectile body portion behind the rotating band. Heretofore the case of such a round has been filled through an off-center hole in the base of the case. This has been found likely to leak due to internal pressure on tiring and the inability of narrow width partitions to avoid distortion and leakage. One previous attempt at solving this diliiculty is disclosed in my prior Patent 2,971,426 dated February 14, 1961 for Method of Loading Fin Stabilized Ammunition and required inverting the projectile, and partially filled case. To load propellant into a case for such a round the projectile body portion must be held well above the front or mouth of the case which cannot otherwise receive the desired propellant.

According to this invention the filling of such a cartridge case with propellant is performed in two steps. In the first, filling of the case with a known measured quantity of propellant through the smaller front end presents no difliculty with the projectile removed. This filling is with enough propellant to be in rear of the ns when the projectile is fixed in place. The filling of the case with sulcient additional propellant to fill the desired space between and above the fins presents more of a problem because it has been thought the fins should not be pushed into a bed of propellant, and unless that is done, the front end of the case is too small for the admission of propellant around the projectile body. Two expedients have been tried. One is a temporary and combustible false bottom placed well above the top of the batch of propellant first to be loaded. This false bottom has to be deep enough to allow the projectile to be far enough out of the case for the case to be filled with the desired second batch of propellant. And this false bottom has to be strong enough to hold this second batch of propellant which is between the fins and keep it from getting under them. The projectile itself is preferably held by a temporary outside support such as an arbor press while this second batch is being filled. To avoid spilling, this second batch of propellant is poured with the aid of a funnel. The false bottom is then moved into an almost negligible small space when the projectile and much of the second batch of propellant between the fins together sink to substantially the top of the first batch of propellant.

The other expedient involves the use of a deformable and largely consumable latex bag with enough air pressure inside to hold the second batch of propellant. On lowering the projectile with this second batch of propellant, the projectile itself or with the assistance of greater pressure or impact will collapse the bag in a mild blow-out allowing the projectile and second batch of propellant to rest on the top of the first batch with the hereinafter mentioned thin consumable liberboard separating the two batches of propellant.

Referring to the drawing:

FIG. 1 shows the case in longitudinal section after being filled with the first batch of propellant.

FIG. 2 illustrates how the case is filled with a second batch of propellant while the projectile is temporarily supported from above the nose or from below the fins.

FIG. 3 is another view of the same case and projectile after a temporary support has been collapsed and the top of the case crimped to the projectile in a depression just behind the rotating band.

The cartridge case 10 is first filled to a desired level with a first batch 13 of propellant before the projectile 11 of the type stabilized by both ns and spin having the tins 12 on a rear portion, is inserted. Then on top of the propellant 13 is placed a false bottom 14 made up in two parts, a collapsible foam cone 15 and a stiff fiberboard 16 just thick enough to support a second measured batch 17 of propellant above it and between the fins. The projectile before being armed is supported from outside and independently of the deformable and consumable temporary false bottom 14 by means of an arbor press 18. A funnel 19 is of assistance in filling the case 10 with the second batch of propellant. The main body 20 of the projectile is supported at a height to provide a channel for movement of this second batch of propellant from the funnel through the forward end of the case into the space between the fins.

The false bottom 14 or temporary and consumable support is comprised of two parts. The first such part including bottom 14 and the slanting sides is a light weight, deformable, yet strong and consumable support, preferably a tubular and tapered length of polystyrene foam or the gas filled bag mentioned later. The second element is a stiff layer of fiberboard 16 about 1%;4 of an inch thick or just thick enough to support the weight of the second batch 17 of propellant above it. Both elements of this support are consumable and under the greater pressure applied to this support this plastic foam or bag is collapsed to much less than about 1/10 its former axial length.

Some idea yof the extent to which the element 15 is capable of being crushed by only a little extra pressure is obtainable from the press as shown in FIG. 3. After the temporary support has been brought to its FIG. 3 position the forward edge of the case is crimped to the projectile, such edge being crimped into a groove 23 just in back of the rotating band 2li. In FIG. 2 the projectile 11 is supported by a threaded arbor 25 extending into the internally threaded nose before being armed.

I claim:

l. In a method for lling a case with propellant and a finned projectile when said propellant is to be filled between the fins of said projectile and also in rear thereof and the case is to be crimped around said projectile forwardly of said fins, the combination therewith of the improvement for filling said case with propellant without having to fill it through a hole in a base of said case and without having to push a finned projectile through a bed of propellant granules with danger of the granules getting jammed and some of them fractured to possess a different burning rate, said improvement comprising filling said case through its fro'nt end with a rst batch of propellant to a heightr just below butl adjacent a rear end of said fins when said projectile is ylater crimped in position in said case, positioning a largely consumable support cover- Y 2. A method accordmg'to claim l in which said step i of temporarily supporting said' projectile and additional dilling of propellant is accomplished with the aid of a deformable, tubular, and consumable polystyrene foam capable of being crushed under additional pressure above that of the projectile and said additional iilling of pro# pellant, and then collapsing said foam support. v

3. A method according to claim 1 intwhich the tem.-k porary supporting of theV projectile includes supporting the same from its nose. Y j

4. A method according to claim 1 in which the temporarily supporting of the Vprojectile is at least to some extent from beneath the `iins and by a consumable fibrous support. Y Y

5. Apparatus for loading propellant into a case to enclose the finned end of a projectile to eliminate the disadvantage of illing said case through an Veccentric iilling opening and Without the danger of forcing the projectile ns through a depth of propellant, said apparatus including means for iilling a predetermined rst quantity of Y propellant into said case through its open upper endrwhen upstanding, means including a collapsible and consumable temporary support for substantially covering said tirst propellant quantity and forV supporting the finned end above said bottom for supporting said projectile nned end spaced above said iirst propellant quantity, means for filling a predetermined quantity of additional propellant into said case above said covering means and about said projectile `iinned end,.and means for collapsing said temporary support and allowing the iinned end of saidprojec-V tilev to be lowered to aheight' adjacent the top of Vsaid rst quantity kof propellant.

6.Y YApparatusV according to claim 5 in which saidtern'- porary support includes tubular polystyrene foam material capable of being collapsed. -V 7. Apparatus according to claim '5Y in which saidtemporary support `includes a consumable,v and stift brous j sheet and a separate support for said projectile.

- 8. Apparatus according to claim 5 in which said projec tile is supported Yfrom its nose temporarily.

9. Apparatus according to claim 5 in Which said projectile istemporarily supported from a rear end of said tins.

References Cited in the file of this patent UNITED STATES PATENTS 3,044,125 A Hosbein July 17., 1962 

1. IN A METHOD FOR FILLING A CASE WITH PROPELLANT AND A FINNED PROJECTILE WHEN SAID PROPELLANT IS TO BE FILLED BETWEEN THE FINS OF SAID PROJECTILE AND ALSO IN REAR THEREOF AND THE CASE IS TO BE CRIMPED AROUND SAID PROJECTILE FORWARDLY OF SAID FINS, THE COMBINATION THEREWITH OF THE IMPROVEMENT FOR FILLING SAID CASE WITH PROPELLANT WITHOUT HAVING TO FILL IT THROUGH A HOLE IN A BASE OF SAID CASE AND WITHOUT HAVING TO PUSH A FINNED PROJECTILE THROUGH A BED OF PROPELLANT GRANULES WITH DANGER OF THE GRANULES GETTING JAMMED AND SOME OF THEM FRACTURED TO POSSESS A DIFFERENT BURNING RATE, SAID IMPROVEMENT COMPRISING FILLING SAID CASE THROUGH ITS FRONT END WITH A FIRST BATCH OF PROPELLANT TO A HEIGHT JUST BELOW BUT ADJACENT A REAR END OF SAID FINS WHEN SAID PROJECTILE IS LATER CRIMPED IN POSITION IN SAID CASE, POSITIONING A LARGELY CONSUMBALE SUPPORT COVERING AND IMMEDIATLY OVERLYING THE TOP OF SAID FIRST PROPELLANT BATCH, TEMPORARILY SUPPORTING SAID PROJECTILE WITH ITS FINS WITHIN SAID CASE AND UPON SAID CONSUMABLE SUPPORT, POURING ADDITIONAL PROPELLANT WITHIN SAID CASE ABOVE THE COVERING SUPPORT AND AROUND SAID PROJECTILE AND FINS THEREOF, AND COLLAPSING SAID CONSUMABLE SUPPORT BY PRESSING SAID PROJECTILE AGAINST SAID CONSUMABLE SUPPORT AND FIRST PROPELLANT BATCH. 